Chances are, this isn't your first mission with Solid Snake. And while you may think you've mastered Metal Gear gameplay before, you're in for a rude awakening the moment you step into Old Snake's new digs.

They say you can't teach an old dog new tricks, but that rule doesn't apply here. Snake's learned lots since his adventure, including an arsenal of new CQC moves with which to dominate the PMC enemies. Some are useful, some are just fun.

Figuring out the new rules of engagement is tough, so we've done it for you. Our extensive basics section goes over the modified gameplay of Metal Gear Solid 4 in practical terms, and we highly suggest reading over the tips therein so you can graduate to a rewarding mastery of the game. When you're done there, check out our walkthrough for boss strategies and info on hidden items. Miss something early and it could hurt you in the long run.